Method for making adsorption device

ABSTRACT

A method for making an adsorption device includes: providing and etching a substrate to form a plurality of receiving grooves spaced apart from each other; forming a magnetic film in each of the plurality of receiving grooves; and forming a magnet in each of the plurality of receiving grooves. Each receiving groove includes a bottom wall and a side wall coupling the bottom wall. The magnetic film covers the bottom wall and the side wall of each of receiving groove.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. Ser. No.16/547,852, filed Aug. 22, 2019, the contents of which are herebyincorporated by reference. The patent application Ser. No. 16/547,852 inturn claims priority from Chinese Patent Application No. 201910605359.4filed on Jul. 5, 2019.

FIELD

The subject matter herein generally relates to a field of manufacturingdisplay panels, and particularly relates to an adsorption device, amethod for making the adsorption device, and a transferring systemhaving the adsorption device.

BACKGROUND

In a manufacturing process of a micro light emitting diode (LED) displaydevice, a large number of LEDs are transferred to a substrate having acircuit. A known method of transferring is to adopt electrostaticattraction, that is, the LEDs to be transferred are held to atransferring substrate by static electricity, then the transferringsubstrate with the LEDs is moved above the substrate, and the staticelectricity is removed to make the LEDs drop onto the substrate.However, the electrostatic charge may damage the circuit on thesubstrate.

Therefore, there is room for improvement in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by wayof embodiments only, with reference to the attached figures.

FIG. 1 is a cross-sectional view of an adsorption device according to anembodiment of the present disclosure.

FIG. 2 is a flowchart showing a method for making the adsorption device.

FIG. 3 is a cross-sectional view illustrating a step S1 of the methodfor making the adsorption device in FIG. 2 .

FIG. 4 is a cross-sectional view illustrating a step S2 of the methodfor making the adsorption device in FIG. 2 .

FIG. 5 is another embodiment of a cross-sectional view illustrating astep S2 of the method for making the adsorption device in FIG. 2 .

FIG. 6 is a cross-sectional view illustrating a step S3 of the methodfor making the adsorption device in FIG. 2 .

FIG. 7 is a cross-sectional view illustrating a step S4 of the methodfor making the adsorption device in FIG. 2 .

FIG. 8 is a cross-sectional view illustrating a step S5 of the methodfor making the adsorption device in FIG. 2 .

FIG. 9 is a cross-sectional view of a transferring system according toan embodiment of the present disclosure.

FIG. 10 is a cross-sectional view showing the transferring system ofFIG. 9 in a working state.

FIG. 11 is another cross-sectional view showing the transferring systemof FIG. 9 in a working state.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein may be practiced without these specificdetails. In other instances, methods, procedures, and components havenot been described in detail so as not to obscure the related relevantfeature being described. Also, the description is not to be consideredas limiting the scope of the embodiments described herein. The drawingsare not necessarily to scale and the proportions of certain parts may beexaggerated to better illustrate details and features of the presentdisclosure.

The term “coupled” is defined as coupled, whether directly or indirectlythrough intervening components, and is not necessarily limited tophysical connections. The connection can be such that the objects arepermanently coupled or releasably coupled. The term “comprising” whenutilized, means “including, but not necessarily limited to”; itspecifically indicates open-ended inclusion or membership in theso-described combination, group, series, and the like.

Referring to FIG. 1 , an adsorption device 10 includes a substrate 11.In this embodiment, the substrate 11 is an aluminum substrate. In otherembodiments, the substrate 11 may be other rigid substrate. A pluralityof receiving grooves 12 spaced apart from each other are defined on asurface 111 of the substrate 11. Each of the receiving grooves 12 has abottom wall 121 and a side wall 122 coupling the bottom wall 121. Inthis embodiment, in order to simplify manufacturing process of theadsorption device 10, each receiving groove 12 has a same shape and asame size. The receiving grooves 12 are arranged in an array. In otherembodiments, the receiving grooves 12 may have different shapes anddifferent sizes, and the arrangement manner of the receiving grooves 12may not be an array, for example, a single row.

As shown in FIG. 1 , a magnetic film 13 is located in each receivinggroove 12. Specifically, each magnetic film 13 completely covers thebottom wall 121 and the side wall 122 of the receiving groove 12.Thickness of the magnetic film 13 in each receiving groove 12 isconstant. The magnetic film 13 is made of a magnetic material. In thisembodiment, the magnetic film 13 is made of a ferromagnetic material ora ferrimagnetic material, such as one or more selected from a groupconsisted of iron, cobalt, and nickel.

As shown in FIG. 1 , the adsorption device 10 further includes aplurality of magnets 14. Each magnet 14 is received in one of thereceiving grooves 12 and partially covered by the magnetic film 13 inthe groove 12. In this embodiment, each magnet 14 includes a bottomsurface 141 facing the bottom wall 121, a top surface 143 opposite tothe bottom surface 141, and a side surface 142 coupling between thebottom surface 141 and the top surface 143. Both the bottom surface 141and the side surface 142 are covered by the magnetic film 13 in thereceiving groove 12. The top surface 143 is exposed from the substrate11.

Each magnet 14 is magnetic and generates a magnetic field. Each magnet14 has a first magnetic pole adjacent to the bottom surface 141 and asecond magnetic pole adjacent to the top surface 143. In thisembodiment, the first magnetic pole is pole N, and the second magneticpole is pole S. In other embodiments, the first magnetic pole is pole S,and the second magnetic pole is pole N. Since each magnet 14 ispartially covered by the magnetic film 13, magnetic lines in themagnetic field generated by the magnet 14 are concentrated within themagnetic film 13 according to the characteristics of the magnetic film13, so that magnetic force on the substrate 11 is concentrated inpositions of each magnet 14. Moreover, the magnetic film 13 preventsmagnetic fields generated by adjacent magnets 14 from affecting eachother, thus the adsorption device 10 has a consistent adsorption effect.

The adsorption device 10 is configured to adsorb target objects 20 bygenerating magnetic force. Each magnet 14 in the adsorption device 10forms an adsorbing position. The adsorption device 10 can absorbmultiple target objects 20 in one single adsorption.

In the present embodiment, the magnet 14 is composed of magnetic powder.When the adsorption device 10 is used, the adsorption device 10 needs tobe inverted such that the surface 111 of the substrate 11 facesdownward. The magnetic powder in the receiving groove 12 may thus dropdown from the receiving groove 12. Even if the magnet 14 is a solidblock, it may easily drop from the receiving groove 12. In the presentembodiment, the adsorption device 10 further includes a protective film15 to cover the receiving groove 12, thus the magnet 14 cannot drop downfrom the receiving groove 12. The protective film 15 covers the topsurface 143 of each magnet 14. In the present embodiment, the protectivefilm 15 is an entire and continuous layer on the surface 111 of thesubstrate 11. In other embodiments, the protective film 15 maynon-continuous layer and include many portions spaced apart from eachother, each portion covers one of the receiving grooves 12. Each portionmay have an area slightly larger than the top surface 143 of each magnet14. In this embodiment, the protective film 15 is made of resin.

FIG. 2 illustrates a flowchart of a method for making an adsorptiondevice. The example method is provided by way of example, as there are avariety of ways to carry out the method. Each block shown in FIG. 5represents one or more processes, methods, or subroutines, carried outin the exemplary method. Furthermore, the illustrated order of blocks isby example only and the order of the blocks can change. The exemplarymethod can begin at block S1 according to the present disclosure.Depending on the embodiment, additional steps can be added, othersremoved, and the ordering of the steps can be changed.

At block S1: a substrate is provided and etched to form a plurality ofreceiving grooves.

A rectangular substrate (not shown) is provided and a surface 111 of therectangular substrate is etched to form the plurality of receivinggrooves 12, as shown in FIG. 3 . The substrate 11 can be etched bylaser. As shown in FIG. 3 , each receiving grooves 12 defines a bottomwall 121 and a side wall 122 coupling the bottom wall 121.

At block S2: a magnetic film is formed in each receiving groove, thefilm is in direct contact with wall of the receiving groove.

As shown in FIG. 4 , a magnetic film 13 is formed on the surface 111 andin the receiving groove 12; the magnetic film 13 covers the bottom wall121 and the side wall 122 of each receiving groove 12. As shown in FIG.5 , the magnetic film 13 is etched and a portion of the magnetic film 13that covers the surface 111 is removed. Only the portion of the magneticfilm 13 which is in the receiving grooves 12 is allowed to remain.

At block S3: a magnet is positioned in each receiving groove and coveredby the magnetic film.

As shown in FIG. 6 , one magnet 14 is formed in each receiving groove 12and is covered by the magnetic film 13. The magnet 14 is flush with thesurface 111. In one embodiment, the magnet 14 is composed of magneticpowder; the magnetic powder infills each receiving groove 12.

At block S4: a protective film is formed on the substrate to close offthe receiving grooves.

As shown in FIG. 7 , in order to prevent the magnets 14 dropping fromthe receiving groove 12, a protective film 15 is formed on the surface111 of the substrate. The protective film 15 covers each receivinggroove 12. The protective film 15 can be made of resin.

At block S5: the magnet in each receiving groove is magnetized such thata side of the magnet adjacent to the protective film and a side of themagnet away from the protective film form opposite magnetic poles.

As shown in FIG. 8 , since magnetic poles of the magnets 14 placed inthe step S3 are irregular, the magnetic poles of the magnets 14 need tobe magnetized. The magnetic poles of each magnet 14 are adjusted so thata side of each magnet 14 adjacent to the bottom wall 121 of thereceiving groove 12 and another side of each magnet 14 away from thebottom wall 121 form opposite magnetic poles. In this embodiment, theside of each magnet 14 adjacent to the bottom wall 121 is arranged to bea magnetic pole N; and the side of each magnet 14 away from the bottomwall 121 is thus a magnetic pole S.

As shown in FIG. 8 , the magnetic poles of the magnets 14 is magnetizedby a permanent magnet 30 having two opposite magnetic poles N and S. Oneof the magnetic poles N and S of the permanent magnet 30 is facing asurface 112 of the substrate 11 opposite to the surface 111 for apredetermined period of time to magnetize the magnets 14. In thisembodiment, the magnetic pole S of the permanent magnet 30 is keptfacing the surface 112 of the substrate 11.

As shown in FIG. 9 , a transferring system 40 includes the adsorptiondevice 10 and a target substrate 41. In this embodiment, thetransferring system 40 is used to complete the transfer of a largenumber of LEDs 42 during a manufacturing process of the display panel.The transferring system 40 is used to transfer a large number of LEDs 42in a single transfer. The LEDs 42 can be, for example, a mini LED, amicro LED, and a conventional size LED. The mini LED described hereinrefers to a sub-millimeter-level LED having a size of about 100 μm to200 μm or more; a micro LED refers to an LED having a size of 100 μm orless.

In this embodiment, the target substrate 41 is an active substrate/arraysubstrate of a display panel. The target substrate 41 defines aplurality of pixel regions, and each of the magnetic units 12corresponds to one pixel region. A plurality of small spots ofanisotropic conductive adhesive 411 are arranged in an array on thetarget substrate 41, and each spot of anisotropic conductive adhesive411 is located in one of the pixel regions. A working process of thetransferring system 40 is as follows.

As shown in FIG. 9 , a surface 111 of the substrate 11 having theprotective film 15 faces the LEDs 42. The LED 42 is made of a materialhaving magnetic properties or the LED 42 contains magnetic particles,and the LEDs 42 have a magnetic pole different from that of the magneticpole of the magnet 14 adjacent to the protective film 15. Thus, the LED42 is subjected to a magnetic force in a direction toward the adsorptiondevice 10 (arrow shown in FIG. 10 ) and is attracted by the magnet 14.Since the plurality of magnets 14 is formed on the substrate 11 and eachmagnet 14 can attract one LED 42, the adsorption device 10 can adsorbmultiple LEDs 42 in a single time. In a manufacturing process of thedisplay panel, the adsorption device 10 can attract and hold tens ofthousands of LEDs 42.

As shown in FIG. 10 , the adsorption device 10 is moved above the targetsubstrate 41 or the target substrate 41 is moved under the adsorptiondevice 10, and the LEDs 42 attracted by the adsorption device 10 are inone-to-one correspondence with the spots of anisotropic conductiveadhesive 411 on the target substrate 41. Each LED 42 contacts one spotof anisotropic conductive adhesive 411. Further, the anisotropicconductive adhesive 411 is thermally cured or UV-cured so that the LEDs42 are adhered to the spots of anisotropic conductive adhesive 411 inone-to-one correspondence.

As shown in FIG. 11 , an adhesion force between the LED 42 and theanisotropic conductive adhesive 411 is greater than the magneticattraction of the LED 42 to the adsorption device 10. When theadsorption device 10 is moved away from the target substrate 41, the LED42 will separate from the adsorption device 10 and be fixed to thetarget substrate 41.

As described above, a large number of LEDs 42 can be transferred ontothe target substrate 41 at one time. Especially when the size of the LED42 is small (such as mini LEDs and Micro LEDs), the above transferringsystem 40 can improve manufacturing efficiency of the display panel.

It is to be understood, even though information and advantages of thepresent embodiments have been set forth in the foregoing description,together with details of the structures and functions of the presentembodiments, the disclosure is illustrative only; changes may be made indetail, especially in matters of shape, size, and arrangement of partswithin the principles of the present embodiments to the full extentindicated by the plain meaning of the terms in which the appended claimsare expressed.

What is claimed is:
 1. A method for making an adsorption device,comprising: providing a substrate and etching the substrate to form aplurality of receiving grooves spaced apart from each other, whereineach of the plurality of receiving grooves comprises a bottom wall and aside wall coupling to the bottom wall; forming a magnetic film in eachof the plurality of receiving grooves, and covering the bottom wall andthe side wall of each of the plurality of receiving grooves with themagnetic film, the magnetic film being made of a magnetic material; andforming a magnet in each of the plurality of receiving grooves, and themagnet being partially covered by the magnetic film.
 2. The method ofclaim 1, further comprising: forming a protective film to cover theplurality of receiving grooves.
 3. The method of claim 2, wherein theprotective film is made of resin.
 4. The method of claim 1, wherein themagnetic film is made of a ferromagnetic material or a ferrimagneticmaterial.
 5. The method of claim 4, wherein the magnetic film is made ofone or more selected from a group consisted of iron, cobalt, and nickel.6. The method of claim 1, wherein the magnet is composed of magneticpowder.
 7. The method of claim 1, further comprising: magnetizing themagnet in each of the plurality of receiving grooves; wherein themagnets facing the bottom wall have a same magnetic pole.
 8. The methodof claim 7, wherein magnetizing the magnet comprises: providing apermanent magnet having a north (N) magnetic pole and a south (S)magnetic pole; and maintaining one of the N magnetic pole or the Smagnetic pole of the permanent magnet facing the magnet for apredetermined period of time.
 9. The method of claim 1, wherein etchingthe substrate comprises etching the substrate by laser.
 10. The methodof claim 1, wherein providing the substrate comprises providing analuminum substrate.
 11. The method of claim 1, wherein the magnetic filmis in direct contact with the bottom wall and the side wall of each ofthe plurality of receiving grooves.
 12. The method of claim 1, whereinthe magnet comprises a bottom surface facing the bottom wall, a topsurface opposite to the bottom surface, and a side surface couplingbetween the bottom surface and the top surface; the bottom surface andthe side surface are covered by the magnetic film, and the top surfaceis exposed from the substrate.
 13. The method of claim 12, wherein thebottom surface and the side surface are in direct contact with themagnetic film.
 14. The method of claim 12, further comprising: forming aprotective film to cover the plurality of receiving grooves.
 15. Themethod of claim 14, wherein the protective film covers the top surfaceof the magnet in each of the plurality of receiving grooves.
 16. Themethod of claim 15, wherein the protective film is an entire andcontinuous layer on the substrate.
 17. The method of claim 15, whereinthe protective film is a non-continuous layer and comprises portionsspaced apart from each other, and each of the portions covers acorresponding one of the plurality of receiving grooves.
 18. The methodof claim 17, wherein each of the portions has an area slightly largerthan the top surface of the magnet.